/**
 * BibSonomy Search - Helper classes for search modules.
 *
 * Copyright (C) 2006 - 2016 Knowledge & Data Engineering Group,
 *                               University of Kassel, Germany
 *                               http://www.kde.cs.uni-kassel.de/
 *                           Data Mining and Information Retrieval Group,
 *                               University of Würzburg, Germany
 *                               http://www.is.informatik.uni-wuerzburg.de/en/dmir/
 *                           L3S Research Center,
 *                               Leibniz University Hannover, Germany
 *                               http://www.l3s.de/
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.bibsonomy.search;

import java.util.Collection;
import java.util.List;
import java.util.Set;

/**
 * used by the search to retrieve friends and group members
 * @author dzo
 */
public interface SearchInfoLogic {
	
	/**
	 * get list of all friends for a given user
	 * 
	 * @param userName the user name
	 * @return all friends of given user 
	 */
	public Collection<String> getFriendsForUser(String userName);
	
	/**
	 * get given group's members
	 * 
	 * @param groupName
	 * @return the members of the group
	 */
	public List<String> getGroupMembersByGroupName(String groupName);
	
	/**
	 * returns the sub tags for a concept
	 * @param concept
	 * @return a list of sub tags
	 */
	public List<String> getSubTagsForConceptTag(String concept);
	
	/**
	 * @param userName
	 * @return a set of usernames, that share documents with the specified user
	 */
	public Set<String> getUserNamesThatShareDocumentsWithUser(String userName);
}
